When providing amplification post-implantation to residual acoustic hearing in the implanted ear, the lower frequency boundary can be modified to minimize or avoid overlap between the frequencies coded through acoustic hearing and those presented through electrical stimulation. This boundary is termed the cross-over frequency (Fc) and the effect of modifying this parameter will be investigated in this study. To avoid the research being confounded by prior bias for a particular frequency allocation, the study will be conducted with newly implanted recipients.